Root traits as predictors of plant and soil functions: aggregating current knowledge to build better foundations for root ecological science

Root systems play key roles in plant functioning and performance and affect many ecosystem processes and functions. Root traits, measured at the plant individual level, or functional parameters, measured at the plant community level, serve as proxies to estimate these functions. The common use of a few easily measurable root morphological and chemical traits have recently contributed to a rapid expansion of the field of root ecology. However, most new insights in root ecology will be gained from broadening our characterisation of roots with a larger suite of traits that are more strongly linked to plant and ecosystem functioning.

In this context, it is critical to identify, critically assess and advertise a larger set of root traits. Root ecologists must face the challenge of adequately delineating and classifying the most relevant root entities (e.g. root parts and root orders) for capturing the plant and ecosystem functions of interest (within boundaries set by time, technological and financial constraints); even the most common root traits are currently measured inconsistently. Adequately characterising root functions requires a-priori knowledge of when (e.g. along seasonal cycles, daily cycles), where (e.g. across soil layers) and how (e.g. practical methods) to sample and measure roots.

Several commentaries and methodological assessments have raised concern about common methodological biases and pitfalls, without reaching consensus between root ecologists. In the context of an exponentially increasing interest in root functions, it is therefore particularly timely and necessary to collectively assemble, sort, and summarise the core of current knowledge on the most relevant sampling practices, traits and measurement methods, and the implications of root trait measures for capturing root functions.

Organising committee

• Grégoire T. Freschet (Senior researcher, Montpellier, France)
• Alexia Stokes (Senior researcher, Montpellier, France)
• Catherine Roumet (Senior researcher, Montpellier, France)
• Monique Weemstra (Post-doc, Montpellier, France)